Flickr vs Thumbsnap

[Simpo Two]

When I upload a 2000px wide photo using Thumbsnap it appears here about half size. Maybe the PH 'autocrunch 750px' is kicking in - and it wrecks photos.

But I see much bigger photos posted here, and they use Flickr. Why does Flickr work and Thumbsnap not? Are there any other quick and easy places to get a decent photo posted?

[GravelBen]

Thumbsnap just seems to mangle image quality in general, maybe they compress file sizes too much to save server space?